230 THE YEAR-BOOK OF AGRICULTURE. 



would be neutralized by the fogs arising from the water and resting over the valleys during 

 the morning, and by the protection afforded by surrounding hills from the cold winds. 



Fruit-growers in the West, after witnessing the repeated destruction of their crops in the 

 valleys, while the trees located on the bleak tops of the surrounding hills were bending down 

 with their luscious burdens, have now discarded the theory with which they set out. 



Dr. Kirtland, of Cleveland, made some interesting experiments on this subject. Supposing 

 that the severity of the frosts in the valleys, compared with its effects on the high lands 

 adjacent, was caused by a current of warm air rushing from the low to the high grounds as 

 the temperature decreased, he stationed himself with a thermometer, lantern, and watch, on 

 a night when a severe frost was expected, on a hill near Lake Erie where the peach crop had 

 never been killed, while his brother was stationed with a thermometer, lantern, and watch, 

 in the valley below. Each made and recorded observations every half hour during the night, 

 and the result was as follows: From sundown until nine o'clock, each thermometer indicated 

 the same degree of temperature. At nine o'clock, the mercury in the valley thermometer 

 commenced sinking, while that on the hill, at the same time, began to rise; and the doctor 

 observed a perceptible current of warm air flowing up from the valley. At twelve o'clock, 

 the thermometer in the valley indicated 12° lower temperature than that on the hill, and 

 about the same difference was observed until daylight in the morning. 



Influence of Situation on the Diseases of Plants. 



M. Mexnevii.i.e, in the Comj^tesRcndus, Paris, expresses the opinion, which he says is based 

 on long observation, that the great epidemic in France which affects so many plants, and more 

 especially the vines, is due in great measure to influences of temperature. Thus, continues 

 M. Mennevillc, it appears to me that all valleys having large streams of water, and so situate 

 a- to be exposed during winter to cold northerly winds, are more or less free from the rava 

 in question. The north slopes of hills are generally free also, and certain elevated traol 

 country, whether in the south or middle of France, suffer but little, unless it be in those 

 spots which are sheltered by irregularities in the soil. 



Protection of Fruit-Trees against Extreme Temperatures. 



Mr. N. T. True, a correspondent of the New England Farmer % writing from Bethel, Maine, 

 gives the following as his experience in cultivating peach-trees and protecting them against 

 the severe cold of a Northern winter. Ue says — 



'•I have peaoh-treeB in their fifth year, which have never suffered in the least from the 

 coldest weather. My place is situated 1° north of Portland, in the White Mountain region, 

 about 7<>0 feet above tide-water. The prevalent idea that extreme cold alone will kill the 

 h. 1 believe, must he abandoned; or, rather, the idea that when the thermometer is 12° 

 below lero it is fatal; 1 have contended for several years, that it is not so much the extreme 

 cold as the strong winds, pelting sleet and snow, and Bndden changes of temperature, that 

 affect the peach. Wo have had the thermometer once at 34°, and at several times from 12° 

 down to that extreme degree of cold, and yet peach-trees that were protected by matting or 

 fir-boughs were n.it injured at all. My practice is this: Late in the fall, 1 draw the limbt 



the tree together and put round some matting — a single fold will answer — drive a Btake down 

 by the side of the tree, and fasten the tree to it. One man can protect from one t.> two hun- 

 i tree- in a day; care should he taken not to unwrap them tOC early in Spring, 



the fruit-buds to the late frosts. 1 also protected a locust-tree in the tame way, 

 simply by lashing > few fir-bought to the north-west side of the tree. It now look- a- bright 

 • it were growing in the latitude of Philadelphia. 



•I can see no r e ason irhj peaches cannot be raised Is any part of Maine simply by pro- 

 tecting them in this way. It may not be known to all that, although SO far to the north, the 



ground i- rarely frosen to any extent In winter. The ■ w- prevent this, so thai it Is 



onlj the topi oi laoh tree- that Deed special protection, it \- useless to attempt the oultira- 



ti •!! of the peach in .Maine without -..me kind of protection; they may Mirvi\e one, two, or 

 even three winters, should tiny be mill, but the fourth may kill them all down." 



